Most analog circuit sections of hybrid digital/analog circuits require passive components, for example capacitors with a high capacitance, a high degree of linearity and high quality. In order to minimize the costs of producing the component, it is desirable that the production of the passive components, in particular capacitance or inductance structures, use as few process steps as possible. Furthermore, the advancing miniaturization of the components and integrated circuits is also accompanied by the demand for the least possible area requirement for the integrated passive components.
U.S. Pat. No. 5,583,359 discloses a capacitance structure for an integrated circuit. In that case, a plurality of metal plates which form the electrodes of a stacked capacitor are arranged one above the other, separated by dielectric layers. Arranged in each plane of a metal plate is a metal line insulated from the respective plate. The metal lines are in each case contact-connected on both sides by via connections, as a result of which, on the one hand, all the plates positioned in odd-numbered fashion in the stack and, on the other hand, all the plates positioned in even-numbered fashion in the stack are electrically connected to one another. By connecting the plates positioned in even-numbered fashion to a first connection line and the plates positioned in odd-numbered fashion to a second connection line, adjacent plates are at a different potential and form pairwise in each case electrodes of a plate capacitor. The capacitance surface area is thus formed by the plate surfaces. An alternative embodiment of the electrodes is provided by forming the plates as strip-type lines arranged parallel to one another.
Further possible configurations of capacitance structures are disclosed in Aparicio, R. and Hajimiri, A.: Capacity Limits and Matching Properties of Integrated Capacitors; IEEE Journal of Solid-State Circuits, Vol. 37, No. 3, 2002, pp. 384–393, which are shown in perspective illustration in FIGS. 5 to 10.
Furthermore, in novel chips in which dielectric regions are formed whose materials have low dielectric constants (for example SiLK, organic material having a dielectric constant of 2.65), black diamond, coral (both carbon-doped oxides having a dielectric constant of less than 3) or porous formations of these dielectrics), mechanical reinforcements are formed in order to avoid damage on account of the low hardness of these dielectric materials under the action of mechanical force on the component.
Components in which both passive components and mechanical supporting structures are present therefore use a relatively large amount of space. What is more, the mechanical supporting structure is no longer used after the completion of the component, in particular after bonding and mounting of the component in the housing.